Regional tunnel management method in a mobile communication system using mobile IP

Abstract

Disclosed is a regional tunnel management method in a mobile communication system using Mobile IP. A mobile node transmits a location registration request to a first GGSN (Gateway GPRS (General Packet Radio Service) Support Node), upon receiving information indicating that the first GGSN supports a foreign agent function and also receiving an Agent Advertisement message with an address of a second GGSN. The information and the Agent Advertisement message are transmitted by the first GGSN. The first GGSN transmits the location registration request to the second GGSN. The second GGSN registers an address of the first GGSN to which the mobile node belongs, and then transmits to a home agent the Location Information message indicating an address of the first GGSN to which the mobile node belongs.

What is claimed is:  
     
         1 . A regional tunnel management method in a mobile communication system using Mobile IP, the mobile communication system including a mobile node, a first GGSN (Gateway GPRS (General Packet Radio Service) Support Node) serving as a foreign agent for storing location information of the mobile node, a second GGSN for storing location information of the first GGSN, and a home agent connected to the second GGSN, for performing data communication with a correspondent node, the method comprising the steps of: 
 transmitting a location registration request from the mobile node to the first GGSN, upon receiving information indicating that the first GGSN supports a foreign agent function and also receiving an Agent Advertisement message with an address of the second GGSN, said information and said Agent Advertisement message being transmitted by the first GGSN;    transmitting the location registration request from the first GGSN to the second GGSN; and    registering by the second GGSN an address of the first GGSN to which the mobile node belongs, and then transmitting to the home agent the Location Information message indicating the address of the first GGSN to which the mobile node belongs.    
     
     
         2 . The method as claimed in  claim 1 , wherein the location registration request transmitted by the mobile node includes the address of the first GGSN to which the mobile node belongs.  
     
     
         3 . The method as claimed in  claim 1 , wherein the Agent Advertisement message is transmitted through a tunnel between the mobile node and the first GGSN.  
     
     
         4 . The method as claimed in  claim 1 , further comprising the steps of: 
 determining by the home agent whether a destination address of the data is identical to the address of the second GGSN, upon receiving data destined for the mobile node from the correspondent node; and    transmitting the data to the second GGSN, if the destination address of the data is identical to the address of the second GGSN.    
     
     
         5 . The method as claimed in  claim 4 , further comprising the step of transmitting the data to the first GGSN from the home agent, if the destination address of the data is not identical to the address of the second GGSN.  
     
     
         6 . The method as claimed in  claim 1 , wherein the Location Information message includes the address of the first GGSN and the address of the second GGSN.  
     
     
         7 . A regional tunnel management method in a mobile communication system using Mobile IP, the mobile communication system including a mobile node, a first GGSN (Gateway GPRS (General Packet Radio Service) Support Node) serving as a foreign agent for storing current location information of the mobile node or serving as a gateway foreign agent for foreign agents existing in a specific region, and a home agent connected to the first GGSN, for performing data communication with a correspondent node, the method comprising the steps of: 
 creating by the mobile node a tunnel and receiving through the created tunnel an Agent Advertisement message indicating whether a second GGSN serves as the foreign agent or the gateway foreign agent, if the mobile node enters a region of the second GGSN;    transmitting a first registration request message for requesting location registration from the mobile node to the second GGSN, if the second GGSN serves as the foreign agent;    transmitting a second registration request message for requesting the location registration for the mobile node from the second GGSN to the first GGSN serving as the gateway foreign agent; and    transmitting a Location Information message indicating location information of the mobile node from the first GGSN to the home agent, upon receiving the second registration request message.    
     
     
         8 . The method as claimed in  claim 7 , wherein the Location Information message includes an IP address of the first GGSN and an IP address of the second GGSN.  
     
     
         9 . The method as claimed in  claim 7 , further comprising the steps of: 
 transmitting the second registration request message for requesting the location registration from the mobile node to the second GGSN, if the second GGSN serves as the gateway foreign agent; and    transmitting the Location Information message indicating the location information of the mobile node from the second GGSN to the home agent, upon receiving the first registration request message.    
     
     
         10 . The method as claimed in  claim 7 , further comprising the step of, upon receiving data destined for the mobile node from the correspondent node after receiving the Location Information message, transmitting the received data from the home agent to the second GGSN to which the mobile node is currently connected.